body{
    background-color: #fff;
    width: 100%;
    height: 2000px;
    max-width:  640px; 
    min-width: 320px;
    margin: 0 auto;
    font-size: 14px;
    color: #666;
    line-height: 1.5;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}
.app{
    height: 45px;
}
a{
    color: #666;
    text-decoration: none;
}
img{
    vertical-align: middle;
}
ul{
    margin: 0;
    padding: 0;
    list-style: none;
}
 .app ul li{
     text-align: center;
     float: left;
     height: 45px;
     background-color: #333333;
     color: #fff;
     line-height: 45px;

 }
 .app ul li:nth-child(1){
     width: 8%;
 }
 .app ul li:nth-child(1) img{
    width: 10px;
    text-align: center;
    
   
}
 .app ul li:nth-child(2){
    width: 10%;
    
}
.app ul li:nth-child(2) img{
    width: 30px;
    vertical-align: middle;
}

.app ul li:nth-child(3){
    width: 57%;
}
.app ul li:nth-child(4){
    width: 25%;
    background-color: red;
}
.search-wrap{
    position: fixed;
   overflow: hidden;
    height: 44px;
    min-width: 320px;
    max-width:  640px; 
    width: 100%;

}
.search-btn{
    position: absolute;
    width: 40px;
    height: 44px;
    top: 0;
    left: 0;
}
.search-btn::before{
    content: "";
    display: block;
    width: 20px;
    height: 18px;
    background: url(../images/selec.png) no-repeat;
    background-size: 20px 18px;
    margin: 14px 0 0 15px;
   }
.search-login{
    position: absolute;
    right: 0;
    width: 40px;
    height: 44px;
    top: 8px;
    color: #fff;
}
.search{
    height: 30px;
    background-color: #fff;
    margin: 0 50px;
    border-radius: 15px;
    margin-top: 7px;
    position: relative;
}
.jd-icon{
    width: 20px;
    height: 15px;
    position: absolute;
    top: 8px  ;
    left: 13px;
    background-color: pink;
    background: url(../images/jd2.png) no-repeat;
    background-size: 20px 15px;

}
.jd-icon::after{
    position: absolute;
    right: -8px;
    top: 0;
    content: "";
    display: block;
    width: 1px;
    height: 15px;
    background-color: #ccc;
}
.sou{
    width: 18px;
    height: 15px;
    background-color: red;
    position: absolute;
    top: 8px;
    left: 50px;
    background: url(../images/jd-sprites.png) no-repeat -81px 0;
    background-size: 200px auto;
}
.slider img{
    width: 100%;
}
nav{
    padding: 5px;
}
nav a{
    float: left;
    width: 20%;
    text-align: center;
}
nav a img{
width: 40px;
margin: 10px 0;
}
nav a span{
    display: block;
}
/* news */
.new{
    margin-top: 20px;
}
.new img{
    width: 100%;
}
.new a{
    box-sizing: border-box;
    float: left;
}
.new a:nth-child(1){
    width: 50%;
}
.new a:nth-child(n+2){
    width: 25%;
    border-left: 1px solid #ccc;
}